This invention relates to chromatography using spherical silica gel.
It is known to select the rate of flow in gradient based on the van Deemter equation or by using standard procedures which have their basis in the van Deemter equation. These conventional procedures work very well with silica particles of irregular shape.
It is also known to improve the resolution of liquid chromatography through the use of spherical packing material. For example, United States published application 2005/0287062 teaches having spherical and porous silica gel with granules comprised between 3 and 45 microns and pores comprised between 30 and 300 Angstrom units. Spherical silica packing was available at least by 1999, as shown by U.S. Pat. No. 6,267,942.
It has been the practice to select the optimum rate of flow of solvent and the gradient used in liquid chromatography based on the van Deemter equation or simply out of habit, originating with the values yielded in the past by the van Deemter equation. The van Deemter equation indicates that a plot of the plate height against rate of flow of the solvent is hyperbolic in shape so that the lowest point on the hyperbola approximates the optimal flow rate of the mobile phase for an efficient column.
Although these practices are long standing and uncontradicted in the field, they do not yield the best results.